In recent years, research has been actively made on robots and animation agents having a speech dialogue function for example. Speech dialogue requires speech recognition. However, the current speech recognition technique can recognize only words and phrases that are registered in advance. This results in an inconvenience when the robots are actually used at home or office for example.
At home and office for example, particular words are used and new words come into existence every day. For example, when a new article is bought by a certain family, the article is frequently named to have a name that is unique to the family. If it is required to verbally instruct a robot to perform a task to find such an article at home, the robot cannot understand the instruction unless the robot knows the word showing the name of the article. An approach may be considered to register a new word by an input to a keyboard. However, this is burdensome. Therefore, robots are desired to have a capability to learn a new name by a speech communication.
Conventionally, many researches have been made on a system for learning the names of objects. However, most of the resultant systems are specialized in a task to learn names by statistically acquiring the names through a set of a plurality of uttelances (Patent Literatures 1 to 3, Non-Patent Literatures 1 and 2).